首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   43篇
  免费   0篇
安全科学   1篇
废物处理   1篇
环保管理   2篇
综合类   20篇
基础理论   5篇
污染及防治   13篇
社会与环境   1篇
  2013年   9篇
  2009年   1篇
  2008年   1篇
  2007年   1篇
  2006年   2篇
  2005年   1篇
  2003年   4篇
  1998年   2篇
  1995年   2篇
  1974年   1篇
  1966年   1篇
  1964年   1篇
  1961年   1篇
  1960年   1篇
  1958年   1篇
  1956年   2篇
  1953年   1篇
  1952年   1篇
  1951年   1篇
  1950年   1篇
  1948年   1篇
  1947年   1篇
  1943年   1篇
  1941年   1篇
  1940年   1篇
  1926年   1篇
  1914年   1篇
  1913年   1篇
排序方式: 共有43条查询结果,搜索用时 187 毫秒
31.
32.
33.
The contribution of ZAMG to MONAROP consists of special weather forecasts to control the SOCs sampling procedure and of the analysis of the specific transport processes for SOCs, which is still in progress.In this paper, air pollutant transport into the Alps is demonstrated by examples of inorganic pollutants: Measurements of NOx and ozone provide evidence for air pollutant transport by local wind systems (valley and slope winds), especially at low elevated sites of the Alps. In addition, trajectory analyses for the high elevation sites demonstrate the importance of large scale synoptic air pollutant transport. The effects of these transport processes with different spatial and temporal scales are governed by the physical and chemical properties of the particular pollutant.First results for the high alpine MONARPOP stations show that air masses from east Europe influence mostly Sonnblick (Austria), whereas the influence of the Po basin is strongest at Weissfluhjoch (Switzerland).  相似文献   
34.
Abstract

Brain tissue samples of nice (7.5 g from 25 mouse brains and lamb (25 g) were homogenized and subcellular fractions prepared in order to assay the distribution of neurotoxic esterase (NTE) activity. The specific inhibitor, N,N‐diisopropylphosphorodiamidic fluoride (mipafox) was synthesized and purified. Maximum specific activity of NTE was reached in the microsomal fraction (110,000 g) while the enzyme activity in the soluble fraction (110,000 g) was extremely low. This subcellular distribution of NTE activity in mammal brains is an original contribution. Brain microsomal fraction is suggested to be a more reliable source for the highest activity of NTE. The specific activity of NTE of lamb brain was much higher than that of mouse brain. This night help interpretation of the characteristic species variation in susceptibility to NTE inhibitors which are known to be potent delayed neurotoxic agents.  相似文献   
35.
This paper briefly reviews the historical development of air pollution training activities in the U. S. It describes the various types of training programs currently available, such as short courses, specialized programs, and university training at the graduate level. The level of financial support and the number of individuals enrolled in these programs are discussed. The paper concludes with an outline of future needs in terms of changes in existing training programs, extension into new areas, and the critical problem of recruitment of qualified candidates for training.  相似文献   
36.
With a specially designed generator, producing an aerosol of concentration, chemical composition, and size distribution similar to incinerator aerosols, a scrubber was tested in the laboratory by sampling before and after the collector. Using an Andersen Sampler as a 7 stage cascade impactor the efficiency for 7 different size classes was determined. This technique provides a rapid and simple method for evaluating the performance of a collector as a function of particle size. The multistage impaction classifies the particles according to their aerodynamic behavior. Gravimetric analysis of each stage eliminates the need for tedious counting and sizing.  相似文献   
37.
38.
Empirically derived relationships associating sediment metal concentrations with degraded ecological conditions provide important information to assess estuarine condition. Resources limit the number, magnitude, and frequency of monitoring activities to acquire these data. Models that use available information and simple statistical relationships to predict sediment metal concentrations could provide an important tool for environmental assessment. We developed 45 predictive models for the total concentrations of copper, lead, mercury, and cadmium in estuarine sediments along the Southern New England and Mid-Atlantic regions of the United States. Using information theoretic model-averaging approaches, we found total developed land and percent silt/clay of estuarine sediment were the most important variables for predicting the presence of all four metals. Estuary area, river flow, tidal range, and total agricultural land varied in their importance. The model-averaged predictions explained 78.4, 70.5, 56.4, and 50.3% of the variation for copper, lead, mercury, and cadmium, respectively. Overall prediction accuracies of selected sediment benchmark values (i.e., effects ranges) were 83.9, 84.8, 78.6, and 92.0% for copper, lead, mercury, and cadmium, respectively. Our results further support the generally accepted conclusion that sediment metal concentrations are best described by the physical characteristics of the estuarine sediment and the total amount of urban land in the contributing watershed. We demonstrated that broad-scale predictive models built from existing monitoring data with information theoretic model-averaging approaches provide valuable predictions of estuarine sediment metal concentrations and show promise for future environmental modeling efforts in other regions.  相似文献   
39.
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号